[MPlayer-G2-dev] libvo2 documentation and pre22 iz out

[Alban Bedel]

Hi D Richard Felker III,

on Thu, 15 May 2003 05:37:31 -0400 you wrote:

> On Thu, May 15, 2003 at 10:50:08AM +0200, Alban Bedel wrote:
> > Hi D Richard Felker III,
> > 
> > on Wed, 14 May 2003 16:05:26 -0400 you wrote:
> > 
> > > At some point, we really need to work out a *good* architecture for
> > > all the *_vid drivers to be in kernelspace, with access to dma, irq,
> > > etc. through the drm (if available)...
> > 
> > Perhaps but as the *_vid drivers are intended for high performance
> > drivers it really depend on the way the card work. With the banshee
> > for example 'internal blit' (ie copy inside the card mem) are
> > essential as they can do scaleing and/or colorspace conversion.
> > Moreover for this card the overlay can only do up scaling so when
> > you want to downscale you have to either don't use the overlay at
> > all or downscale when copying to the overlay mem and resetup
> > the overlay source size.
> > So i doubt that we can really get every bit of performance out of
> > every card with a general approch.
> > Perhaps that most modern cards can be well handled in general way
> > but i doubt we'll find an interface wich will suit every kind of
> > card with scaleing and/or colorspace conversion caps.
> 
> As far as I can tell, all we need so far is a CAN_DOWNSCALE flag and a
> list of supported colorspaces... Doesn't sound too hard. VO drivers
> are already required to identify whether or not they can downscale, so
> the vo driver could just return the flag from the *_vid driver.
Sure. My point was more that in some case it's possible but then it
requiere some special trick wich can be hardly handled in a generic
way.

> As for non-overlay-based scalers, I think they're best kept separate.
> I was talking about a general driver architecture for video overlays
> (like vidix was supposed to be, except non-broken), not for all video
> scaling and colorspace conversion stuff.
Ok then tdfx_vid should probaly be renamed to something else ;)
	Albeu